Surface deposition of 222Rn decay products with and without enhanced air motion
The effectiveness of fan-induced air motion in reducing airborne activities of short-lived /sup 222/Rn decay products was evaluated in a 78.5-m3 chamber. Observed reductions were as high as 50% for 218Po (RaA), 79% for /sup 214/Pb (RaB), and 86% for /sup 214/Bi (RaC). Activity measurements of these nuclides on chamber and fan surfaces, along with airborne activities, were used to calculate material balances. Greater than about 90% of deposited activity was found on chamber surfaces, although areal activity densities were higher on fan surfaces. Deposition velocities for decay products not attached to particles were 2.3 mm s-1 when no fans were in operation and 9.2 to 13 mm s-1 when fans were used. Mean boundary layer thicknesses for unattached decay products were estimated to be about four times the recoil distance of a /sup 214/Pb atom when no fans were used and about equal to the recoil distance when fans were used.
- Research Organization:
- Harvard Univ. School of Public Health, Boston, MA
- OSTI ID:
- 5010675
- Journal Information:
- Health Phys.; (United States), Journal Name: Health Phys.; (United States) Vol. 3; ISSN HLTPA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
Atmospheric-- Radioactive Materials Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
AIR FLOW
ALPHA DECAY RADIOISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BISMUTH 214
BISMUTH ISOTOPES
DAYS LIVING RADIOISOTOPES
DEPOSITION
ENVIRONMENTAL EXPOSURE
EVEN-EVEN NUCLEI
FLUID FLOW
GAS FLOW
HEAVY NUCLEI
ISOTOPES
LEAD 214
LEAD ISOTOPES
MINUTES LIVING RADIOISOTOPES
MONITORING
NATURAL RADIOACTIVITY
NUCLEI
ODD-ODD NUCLEI
POLONIUM 218
POLONIUM ISOTOPES
RADIATION MONITORING
RADIOACTIVITY
RADIOISOTOPES
RADON 222
RADON ISOTOPES
SURFACES